The proposed research is motivated by two related viewpoints which both assume that dynamic information is important to mental representations. One viewpoint claims that mental representations are dynamic, meaning that a temporal dimension is integral to the representation, even when the stimulus being represented is static. A second viewpoint sees information pick-up as "transitional perception", meaning that perceivers are particularly sensitive to the transitions between states and not just the end states themselves, for both static and dynamic stimuli. Both of these perspectives motivate experiments demonstrating that some static stimuli are perceived and represented in terms of dynamic processes. For instance, handwriting recognition is understood as involving knowledge of construction processes, such that a handwritten letter can be thought of as a static trace of a dynamic process. Similarly, the perception of snapshots of real-world action scenes is understood as involving the mental unfreezing of the action frozen in the photograph. A related research strategy is to investigate the internalization of physical constraints, such as momentum and gravitational acceleration, on moving objects. There are two reasons for this second focus; first, if the representation of static stimuli involves knowledge of past and future events then people's representations of moving objects should reflect properties of moving objects in the world; second, if dynamic information is integral to mental representations it should be describable and lawful. The proposed research, when carried out, should tell us more about the role of dynamic information in mental representations of both static and phenomenonally dynamic stimuli.